Anode Myths part1.

[ditchcrawler]

26 minutes ago, WotEver said:

Nope, it was impressed into the material...

Simply put, if the galvanic action of the anode is insufficient on its own then you give it a little help with a power supply.

 

Knowing what size and type (not power) of anode to use, and exactly what voltage needs to be applied to it is a science. 

If I trailed them on wires I could pick up the stunned fish behind me, might get a Zander for dinner. When I was at work one of my tasks was to ensure it was off before we had any divers working in the area.

[Chris and PJ]

2 minutes ago, ditchcrawler said:

If I trailed them on wires I could pick up the stunned fish behind me, might get a Zander for dinner. When I was at work one of my tasks was to ensure it was off before we had any divers working in the area.

hey who did you work for. I started in the early 80s with BIX offshore then Stolt Seaway and ended up with Gulmar

[Guest]

1 hour ago, Machpoint005 said:

 

I'm glad (but not surprised) that you know what I'm on about! It's still no good, though: he will not admit that his original use of the term "power" was simply incorrect. He just thinks we don't get it.

 

Apparently it is splitting hairs to insist on the correct use of technical terms in a technical post.

 

 

Grow up.

[WotEver]

1 hour ago, Chris and PJ said:

be interesting for us all to hear how you get anything other than power from a power supply

Yep, you get power from a power supply, correct.

1 hour ago, ditchcrawler said:

If I trailed them on wires I could pick up the stunned fish behind me, might get a Zander for dinner. When I was at work one of my tasks was to ensure it was off before we had any divers working in the area.

I’m told they’re really good eating. 

 

Zander that is, not divers. 

[Chris and PJ]

17 hours ago, WotEver said:

Nope, it was impressed into the material...

Simply put, if the galvanic action of the anode is insufficient on its own then you give it a little help with a power supply.

 

Knowing what size and type (not power) of anode to use, and exactly what voltage needs to be applied to it is a science. 

You show complete lack of understanding of what galvanic corrosion protection is.

The bare roots of the subject, when considering the corrosion of metals in water are described in the Pourbaix diagrams for each submerged metal.

Let take the Pourbaix diagram for mild steel in water below:

 

The term SHE means Standard Hydrogen Electrode. SHE half-cells are not practical out side of a laboratory so corrosion engineers use Ag/AgCl half-cells instead so there is a slight difference in real world voltages measured against this diagram.

Mild Steel when measured in canal water against Ag/AgCl shows a potential (volts) of around -0.4 volts. I know this, because I have measured it.

Looking at the diagram at -0.4v the word `red` indicates the formation of Fe III (one of the 3 forms of iron oxide = rust)

The diagram indicates that if you can push the potential of the mild steel to be more negative so that it sits in the immunity zone.

Industry goes for -0.800 volts. So it will NOT corrode (rust). Can not corrode. Is resistant to corrosion. Too cathodic to corrode.

The ONLY way of doing this is by the application of POWER / Energy/ Watts/ whatever you want to call it.

The most convenient way of producing this voltage shift is to electrically connect a sacrificial anode 

A Military spec. Magnesium anode in fresh water produces -1.5 volts in open circuit when measured  against Ag/AgCl

When this Mag Anode is connected to the mild steel its voltage drops due to the current required to change the potential of the steel, to a level of about -0.800 v 

When matched to its operating environment the size shape and weight of the anode determines how much current it can supply  and for how long. Current times volt = power in Watts.

The only way of measuring these potentials is with a Half-Cell. Anything else is pure speculation banded about by those with big egos and little knowledge mixing apples with oranges

The above is scientific fact.

 

The added advantage of achieving these potentials in water is that a powerful Ferrous Hydroxide film (coating) is produced that is highly resistant to the dissolved Oxygen in water.

Stopping the formation of pits. Microbe attack and metal loss.

 

 

0

[WotEver]

1 hour ago, Chris and PJ said:

You show complete lack of understanding of what galvanic corrosion protection is.

The bare roots of the subject, when considering the corrosion of metals in water are described in the Pourbaix diagrams for each submerged metal.

Let take the Pourbaix diagram for mild steel in water below:

 

The term SHE means Standard Hydrogen Electrode. SHE half-cells are not practical out side of a laboratory so corrosion engineers use Ag/AgCl half-cells instead so there is a slight difference in real world voltages measured against this diagram.

Mild Steel when measured in canal water against Ag/AgCl shows a potential (volts) of around -0.4 volts. I know this, because I have measured it.

Looking at the diagram at -0.4v the word `red` indicates the formation of Fe III (one of the 3 forms of iron oxide = rust)

The diagram indicates that if you can push the potential of the mild steel to be more negative so that it sits in the immunity zone.

Industry goes for -0.800 volts. So it will NOT corrode (rust). Can not corrode. Is resistant to corrosion. Too cathodic to corrode.

The ONLY way of doing this is by the application of POWER / Energy/ Watts/ whatever you want to call it.

The most convenient way of producing this voltage shift is to electrically connect a sacrificial anode 

A Military spec. Magnesium anode in fresh water produces -1.5 volts in open circuit when measured  against Ag/AgCl

When this Mag Anode is connected to the mild steel its voltage drops due to the current required to change the potential of the steel, to a level of about -0.800 v 

When matched to its operating environment the size shape and weight of the anode determines how much current it can supply  and for how long. Current times volt = power in Watts.

The only way of measuring these potentials is with a Half-Cell. Anything else is pure speculation banded about by those with big egos and little knowledge mixing apples with oranges

The above is scientific fact.

 

The added advantage of achieving these potentials in water is that a powerful Ferrous Hydroxide film (coating) is produced that is highly resistant to the dissolved Oxygen in water.

Stopping the formation of pits. Microbe attack and metal loss.

Which is a long-winded way of repeating exactly what I said

[Machpoint005]

3 hours ago, Chris and PJ said:

The ONLY way of doing this is by the application of POWER / Energy/ Watts/ whatever you want to call it.

 

What do YOU want to call it? Power can be measured in watts.

Energy can't.

[Chris and PJ]

2 hours ago, Machpoint005 said:

 

What do YOU want to call it? Power can be measured in watts.

Energy can't.

Ok you don't understand so I need to explain it in a different way.

I do think I understand what you are trying to Say

All metals to be usable by man, with a very few exceptions like gold. Only exist on this planet as oxides or salts. (ores)

To turn these ores into a usable form Man through various processes. Smelting for iron and steel. Electrolysis for metals like Magnesium force electrons back into the ore .

These man made metals are defying the second law of thermodynamics by containing too much energy.

Because this law defines what is best described as natures will to turn everything into its lowest energy form. (Entropy)

In the case of steel to loose electrons and rust even in dry air

The Galvanic series lists these metals in terms of this energy. Volts

 Magnesium contains more energy than steel so is more active

The Pourbaix diagrams describe how these energy levels are effected by the environment (water) and described in Volts

 

Because nature demands corrosion, in water material is returned to its salt state and an electron is released thus in physics it is said that `Work has been done`

The fact that Magnesium looses mass, indicates that work has been done and there has been a depletion in the electrons (energy) you cant have one without the other.

Therefore a flow of electrons (energy) and work being done can only be described in Watts the unit of power.

 

If you have a better explanation for the existence of a form of energy in the context of galvanic corrosion that explains how anodes work then please describe it.

Please also explain your statement (in the context of galvanic corrosion) that. I quote Energy cant be measured in Watts

[WotEver]

6 minutes ago, Chris and PJ said:

Please also explain your statement (in the context of galvanic corrosion) that. I quote Energy cant be measured in Watts

I’m not the poster who wrote that but the answer is pretty simple.

 

Energy is the total amount of work done, and power is how fast you can do it. In other words, power is energy per unit of time. Power is measured in watts. Energy is measured in watt-hours or Joules. 

 

Or, if you prefer, Energy is the strength needed to perform work, while the rate at which work is performed is called power. 

 

Or, if you prefer, to perform a particular physical operation will require energy. If you perform that operation faster you will expend more power than if you were to do it slowly. Take an accelerating car as an example; faster acceleration will require higher bhp (power). 

 

So going back to the beginning of this diversion, a metal can contain more energy (magnesium vs steel for example), but it can’t contain more power. 

[Chris and PJ]

10 minutes ago, WotEver said:

I’m not the poster who wrote that but the answer is pretty simple.

 

Energy is the total amount of work done, and power is how fast you can do it. In other words, power is energy per unit of time. Power is measured in watts. Energy is measured in watt-hours or Joules. 

 

Or, if you prefer, Energy is the strength needed to perform work, while the rate at which work is performed is called power. 

 

Or, if you prefer, to perform a particular physical operation will require energy. If you perform that operation faster you will expend more power than if you were to do it slowly. Take an accelerating car as an example; faster acceleration will require higher bhp (power). 

 

So going back to the beginning of this diversion, a metal can contain more energy (magnesium vs steel for example), but it can’t contain more power. 

So what is your point

When you connect steel to magnesium in water energy transfers. and you measure the work done in watts

The guy is saying that the energy flowing in the case of galvanic corrosion cant be measured in watts

and in an attempt not to patronise I did not ask him to ask a 15 year old

[WotEver]

6 minutes ago, Chris and PJ said:

The guy is saying that the energy flowing in the case of galvanic corrosion cant be measured in watts

He’s correct. Energy can be measured in Joules or watt-hours, it can’t be measured in Watts. Power however can be measured in watts. He’s merely asking that you remain dimensionally accurate if you’re going to describe a technical point. 

[Chris and PJ]

14 hours ago, WotEver said:

He’s correct. Energy can be measured in Joules or watt-hours, it can’t be measured in Watts. Power however can be measured in watts. He’s merely asking that you remain dimensionally accurate if you’re going to describe a technical point. 

Complete and utterly pedantic claptrap hair splitting. That if paid attention to, would confuse the reader into thinking that a Sacrificial Anode is something other, than a simple power source.

Be assured than Sacrificial Anodes are selected by their power output and duration. For the sole purpose of driving the cathode more negative and serve no other purpose.

 

I  inserted a glaring technical nonsense into my posting No. 83. (steel will rust in dry air) That anybody with even the most basic understanding of Galvanic Corrosion would pick up. To see if those, pompously demanding dimensional accuracy over easy understanding, actually know anything at all about the subject.

Steel does not rust in dry air, there being no electrolyte!

 

The key principle that I am attempting to impart to this community is that corrosion is controllable, predictable and quantifiable. Sadly corrosion mechanisms are surrounded by myths

When I read posts describing expensive hull corrosion that is mostly attributed to shore power connections, with electricians measuring this and that, then speculating on causes.

From the perspective of a corrosion engineer it all seems nonsense for the following reason:

 

Any electrical influence on a steel hull in water that changes its electrical potential in relation to the water. Changes its corrosion characteristics.

These changes can be simply measured with a Half-Cell.

If damaging potentials are detected  the source can be simply identified. Boat next door?--- kind of important that you find out

For instance dip the Half-Cell and see if the measurement rises or falls as you connect and disconnect your shore power . If the reading changes, so does your rate of corrosion.

The same for all your internal electrics if switching on off and something changes the reading its changed you corrosion rate.

The Half-Cell offers the only scientifically sound indisputable way of doing this

If you find that your corrosion potential change can be attributed to a third party's failure to take reasonable care or apply reasonable expertise  ( I am not a lawyer)

These readings when confirmed (by qualified corrosion engineer and loss quantified) give you your only route to legal redress.

 

As I have said before. I am happy to help anybody with the loan of equipment and / or expertise. Of course in the strictest confidence.

 

 

 

[WotEver]

29 minutes ago, Chris and PJ said:

I  inserted a glaring technical nonsense into my posting No. 83

Do you really think anybody actually reads all of your pretentious ramblings?

29 minutes ago, Chris and PJ said:

The key principle that I am attempting to impart to this community is that corrosion is controllable, predictable and quantifiable

Yes, and we all understood that from your very first post. 

29 minutes ago, Chris and PJ said:

The Half-Cell offers the only scientifically sound indisputable way of doing this

Yes, we know. Why do you feel the need to repeat the fact endlessly?

Edited September 21, 2019 by WotEver
Added a bit

[WotEver]

21 hours ago, Chris and PJ said:

Complete and utterly pedantic claptrap hair splitting.

If you say so

Edited September 22, 2019 by WotEver

[Arthur Marshall]

Having battered my way through most of this lot, i still have no idea as to whether anodes are supposed to work or not.  Although, as my engine doesn't at the moment anyway, I don't suppose it matters much. Not to me, anyway.  And I reckon my brand new bottom will last the rest of my boating life anyway, with or without the damn things.

[Captain Pegg]

6 minutes ago, Arthur Marshall said:

Having battered my way through most of this lot, i still have no idea as to whether anodes are supposed to work or not.  Although, as my engine doesn't at the moment anyway, I don't suppose it matters much. Not to me, anyway.  And I reckon my brand new bottom will last the rest of my boating life anyway, with or without the damn things.

Quite so Arthur. @Chris and PJ told us they were intending to take up boating in retirement but 32 posts later have done nothing but argue the toss about anodes and done nothing to really enlighten the folks on here who might be interested in that subject.

 

I’d suggest to them that if they really do want to take up boating that they post on one of welcome threads telling us about their boating plans. Otherwise I think it’s not unreasonable to assume the real reason for their joining the forum relates to a little post-retirement business of theirs.

 

I’ve also been reading the thread waiting for something useful to come of it; at which point I may just ask a couple of questions of my own.

 

JP

Edited September 21, 2019 by Captain Pegg

[WotEver]

19 hours ago, Arthur Marshall said:

Having battered my way through most of this lot, i still have no idea as to whether anodes are supposed to work or not. 

Yup, they work. They may not work well enough, depending on the boat’s environment but unless you’re bound to a permanent mooring then the environment is a movable feast anyway. 

 

The best protection against corrosion for a narrowboat hull is a good coat of well-adhered blacking. 

Edited September 22, 2019 by WotEver
Added a worm

[Machpoint005]

11 hours ago, Chris and PJ said:

Complete and utterly pedantic claptrap hair splitting.

 

If that is your attitude to accuracy and precision it speaks volumes about the validity of your argument.  

11 hours ago, Chris and PJ said:

confuse the reader into thinking that a Sacrificial Anode is something other, than a simple power source.

 

It is a reservoir of sacrifical metal, however you look at it. 

 

Do you buy your energy from the electricity supplier in kilowatts or kilowatt-hours? Try asking them for a price per kilowatt and see how far you get.

[Slim]

I'm laying here in bed trying to get to sleep and I think I have found the answer... This topic as started by the OP. I strongly suspect he's trying to show how clever he is!

Good night ?

[MtB]

51 minutes ago, Slim said:

I'm laying here in bed trying to get to sleep and I think I have found the answer... This topic as started by the OP. I strongly suspect he's trying to show how clever he is!

Good night ?

 

I thought that too.

 

And there is another thread by another new poster started with exactly the same intention, or so it struck me. 

 

 

 

[TheBiscuits]

13 hours ago, Chris and PJ said:

Steel does not rust in dry air, there being no electrolyte!

Oh good.

 

Can you explain where I can get enough dry air from to wrap around my boat please?

 

I'm in the UK if it helps ... and my superstructure rusts too. 

 

I understand they have vehicle graveyards/storage compounds in Arizona because the air is dry enough to store steel items long term without rusting, but that doesn't really help me in Lancashire.

[MtB]

Curious, the steel rusting in dry air thing. 

 

When I read it, I thought thats rubbish and immediately decided the OP did not understand his subject so I dismissed everything he was saying and marked him down as a bullshitter.

 

 

[reg]

When is part 2 coming out? 

 

Edited September 22, 2019 by reg

[WotEver]

7 hours ago, Mike the Boilerman said:

Curious, the steel rusting in dry air thing. 

 

When I read it, I thought thats rubbish and immediately decided the OP did not understand his subject so I dismissed everything he was saying and marked him down as a bullshitter.

You did better than me for reading that far. I only skimmed it and missed that part. Regardless, I believe your conclusion isn’t far off the mark anyway. 

[MtB]

3 minutes ago, WotEver said:

You did better than me for reading that far. I only skimmed it and missed that part. Regardless, I believe your conclusion isn’t far off the mark anyway. 

 

I think he is only here to ramp the website he links to. The confusing and jargon-heavy writing style is the same.